Unitrode PWM Controller Sets Industry Standard for Battery Efficiency At High Frequencies.

MERRIMACK, N.H.--(BUSINESS WIRE)--June 23, 1999--

Unitrode Corporation (NYSE:UTR), a manufacturer of analog/linear and mixed-signal integrated circuits, modules, and nonvolatile products, today announces the UCC39421/2 family of multimode high-frequency PWM controllers, optimized for low-power, portable applications.

Ideal for applications such as cell phones, pagers, PDAs, and other handheld devices, the UCC39421/2 provides greater than 95% efficiency in various topologies. Of particular importance to designers is the state-of-the-art capability for configuration at fixed frequencies as high as 2MHz. The circuit is ideally suited for multi-chemistry battery applications, whether using alkaline, NiMH rechargeable, or lithium-ion rechargeable cells.

According to Mickey McClure, Unitrode Portable Product Marketing Manager, the UCC39421/2 family offers "the most flexible and efficient solution available today for multi-chemistry and multi-mode portable, low-power applications." He added, "Its main technical feature is the efficiency achieved during high frequency operation. As a result of the circuit's innovative design, it provides a critical advantage when used in space-constrained portable equipment because the high-frequency operation permits smaller magnetics."

Specific features of the UCC39421 family:

-- 95 percent efficient, current-mode DC/DC conversion in boost,

flyback, and SEPIC (Single-Ended Primary Inductance Converter)

control topologies.

-- Can operate down to 1.8V input and drive either external

p-channel or n-channel MOSFETs.

-- All converter topologies can be configured to operate at fixed

frequencies as high as 2MHz.

-- The boost topology of the UCC39421/2 is ideally suited for

portable applications where primary power is provided from

two or three primary alkaline or NiMH rechargeable

batteries.

-- The wide voltage range of lithium-ion rechargable cells is

well-suited to applications using the UCC39421/2 flyback and

SEPIC topologies.

-- A user-programmable current threshold comparator commands

variable-frequency operation for optimum efficiency at low output

power levels. The converter frequency can also be synchronized to

an external clock.

-- A programmable power-on-reset function and an uncommitted

comparator for low-voltage detection. as well as pulse-by-pulse

current limiting and low current shutdown (5uA).

Pricing and Availability

The UCC39421 is priced at $3.00, and the UCC39422 is priced at $3.35, both in 1,000-piece quantities. Samples are available now from Unitrode. Consult the factory for production lead times. The UCC39421 is offered in 16-pin TSSOP (PW) or DIL (N) packages, and the UCC39422 is offered in 20-pin PW or N packages. Temperature ranges are -40 degrees C to 85 degrees C for the UCC29421/2, and 0 degrees C to 70 degrees C for the UCC39421/2.

For more information, see http://www.unitrode.com/products/portable/ucc39421.htm .

About Unitrode

Unitrode designs and manufactures analog/linear and mixed-signal integrated circuits, modules, and nonvolatile products, principally to perform power management, portable power, and interface functions. Its products, branded under Unitrode and Benchmarq, are sold throughout the world for a variety of computer, tele- and data-communications, defense/aerospace, industrial, and consumer applications. Further information about Unitrode may be found at the Company's homepage site: http://www.unitrode.com.